Vehicle wheel for passenger cars

ABSTRACT

Vehicle wheel comprising a rim part and a disc part formed from a one-piece sheet metal blank and including a central portion with bolt holes and a plurality of radially extending spoke arrangements merging into a disc edge delimiting together with the spoke arrangements ventilation apertures which extend over the region between the edge webs and the disc edge. In order to create steel wheels with four-hole fixing in which high strength and stiffness are achieved the number of spoke arrangements and of bolt holes is four and these are in each case arranged mirror-symmetrically with respect to a common radial line, with the width of each spoke arrangement narrowing radially towards the outside and each ventilation aperture extending in the circumferential direction over an arc length of more than ⅙ of the circumference of the disc part. Further, each ventilation aperture is having on a radial line a maximum radial clear width which is equal to or preferably greater than the radial width of the metal portion of the disc part on the same radial line.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage of International Application No.PCT/IB2014/059136 filed Feb. 20, 2014, the disclosures of which areincorporated herein by reference in entirety, and which claimed priorityto German Patent Application No. 20 2013 100 875.3, filed Feb. 28, 2013,the disclosures of which are incorporated herein by reference inentirety.

BACKGROUND OF THE INVENTION

The invention relates to a vehicle wheel, in particular for passengercars, comprising a rim part for receiving a tyre and a disc part whichis connected to the rim part and is formed from a one-piece sheet metalblank by forming and cutting or punching, which disc part includes acentral portion having bolt holes for wheel bolts and a central aperturefor a vehicle hub and a plurality of radially extending spokearrangements, formed by shaping the sheet metal, for transmitting forcebetween vehicle hub and rim part, each spoke arrangement being providedwith a radially extending central web which merges on each side into aradially extending lateral web, bent outwardly from the plane of thecentral web, and then into an edge web bent back again with respect tothe lateral web, the radially outer ends of the central webs and of thelateral webs merging into a circumferential annular disc edge orientedprecisely parallel or substantially parallel axially to the wheel axisand connecting all the spoke arrangements to one another, which discedge is formed integrally from the sheet metal, forms the connectingpart for the connection between rim part and disc part and in each casedelimits, together with the edge webs of adjacent spoke arrangements,ventilation apertures which extend over the region between the edge websand the disc edge.

A generic vehicle wheel for passenger cars, on which the preamble ofclaim 1 is based, is known from EP 1 262 333 A2 of the applicant, isusually referred to commercially as a “structured wheel” and is marketedby the applicant under the trade name “Versastyle®”. Through itsconstruction this vehicle wheel, which is produced from a steel blank byshaping and has comparatively large-area ventilation apertures, cancompete with aluminium wheels not only economically in terms of weightbut also in terms of style, on the one hand because the wheel has astriking appearance resulting from the interplay between the multipleshaping of the spoke arrangements and the large ventilation aperturesand, on the other, because different hub caps can be used with thisvehicle wheel without disadvantage to the total weight of the wheelfitted with hub cap, as compared to a comparable cast-aluminium vehiclewheel.

The vehicle wheel known from EP 1 262 333 A1 forms a new type ofembossed steel wheel for passenger cars which hitherto has been producedonly with five bolt holes and five spoke arrangements distributedsymmetrically with respect to the bolt holes. Other manufacturers havealso proposed innovations to this type of vehicle wheel, as shown, forexample, by U.S. Pat. No. 7,104,611 B2 or EP 1 790 499 A1, in whichminimal modifications to the vehicle wheel according to EP 1 262 333 A1are described and all of which start from this vehicle wheel as thenearest prior art.

Passenger cars, especially in the small, compact and mid-sized classes,frequently require wheels with four-hole fixing. The wheel structureaccording to EP 1 262 333 A2 thus gives rise to a steel vehicle wheelwith four spoke arrangements and four bolt holes.

BRIEF SUMMARY OF THE INVENTION

It is a feature of the invention to create steel wheels for vehicleswith four-hole fixing in which high strength and stiffness are achievedin conjunction with ventilation apertures of especially large area.

This feature is achieved according to the invention in that the numberof spoke arrangements and the number of bolt holes is four and one spokearrangement and one bolt hole are in each case arrangedmirror-symmetrically with respect to a common radial line, the width ofeach spoke arrangement becoming constantly narrower from the centralportion radially towards the outside, each ventilation apertureextending in the circumferential direction, at the narrowest point ofthe spoke arrangements, over an arc length of more than ⅙ of thecircumference of the disc part, at least on this reference circle, andeach ventilation aperture having a maximum radial clear width, on aradial line disposed midway between two adjacent spoke arrangements,which is greater than the radial width of the metal portion of the discpart on the same radial line.

In the vehicle wheel according to the invention, having four bolt holesand four spoke arrangements, each of which spoke arrangements extends inprolongation of a bolt hole, each ventilation aperture has, according tothe invention, at the narrowest point of the spoke arrangements, an arclength of more than ⅙ of the circumference of the disc part on the samereference circle on which the narrowest points of the spoke arrangementslie, and at the same time each ventilation aperture extends in theradial direction over a clear width which is equal to or preferablygreater than the metal portion between the centre hole and the region ofthe disc part bordering the ventilation aperture radially on the inside,which region is formed at this location by the convergent edge webs ofthe adjacent spoke arrangements. The ratio of the radial width of themetal portion of the disc part to the clear width of a ventilationaperture on the same radial line is then either approximately equal to 1or preferably less than 1.

It is especially advantageous if the ratio of radial width to clearwidth, and therefore the quotient of radial width/clear width, is from0.85 to 0.95 and preferably is 0.9±0.02.

Further preferably, the central webs of all the spoke arrangements mayeach extend, in a radial partial section, in a plane disposedorthogonally to the wheel axis, each partial section in turn having alength which is equal to or preferably greater than half the clear widthof the ventilation apertures. The quotient of partial section/clearwidth is preferably from 0.6 to 0.7.

The edge webs may have a depth which, starting from a radial linebisecting a ventilation aperture midway between two adjacent spokearrangements, at first increases continuously and then decreasescontinuously again. The edge webs therefore have their narrowest zones,firstly, on the radial line bisecting the ventilation apertures and,secondly, at the outer ends of the spokes.

Further advantageously, the distance between the lateral webs of a spokearrangement, starting from the central portion in the direction of theouter spoke ends, may first narrow continuously, and then widen again.This measure also contributes, like the aforementioned measures, toimproving the stiffness and load-bearing capacity of the disc partdespite the large-area ventilation apertures.

It is additionally advantageous if the maximum relative deformationdepth between the central web and the transition of the lateral web tothe edge web, in the range of extent of the ventilation apertures, isfrom 10 mm to 30 mm, the minimum depth in the region of the radialpartial section preferably being greater than 10 mm.

The outside edges of the edge webs bordering the ventilation aperturemay be disposed, in radially outer regions of the ventilation apertures,at an angle of 6° to 10°, preferably 8°±1°, to the common radial line ofbolt hole and spoke arrangement. Alternatively or additionally, theoutside edges of the edge webs and of the disc edge directly borderingthe ventilation aperture may be disposed, or cut off, obliquely withrespect to the wheel axis.

Other advantages of this invention will become apparent to those skilledin the art from the following detailed description of the preferredembodiments, when read in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a plan view of a vehicle wheel according to the inventionin a first exemplary embodiment;

FIG. 2 shows the vehicle wheel of FIG. 1 in a perspective view;

FIG. 3 shows a sectional view along III-III in FIG. 1;

FIG. 4 shows schematically a section through one of the spokearrangements;

FIG. 5 shows a plan view of a vehicle wheel according to the inventionin a second exemplary embodiment; and

FIG. 6 shows the vehicle wheel of FIG. 5 in a sectional view along VI-VIin FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION

In FIGS. 1 to 3, a vehicle wheel according to the invention in a firstexemplary embodiment, consisting essentially of a circular rim part 1having multiple steps, to the inner side of which a disc part 10 isfastened, is denoted as a whole by reference 50. The rim part 1, whichreceives a tyre (not shown), is fastened via a central portion 11 of thedisc part 10 to a hub (not shown) of a vehicle (also not shown), inparticular a passenger car. The rim part 1 extends in a very largelyrotationally symmetrical manner around the wheel axis R, which generallycoincides with the axis of the vehicle hub in the installed state of thevehicle wheel 50. In the exemplary embodiments shown, both the rim part1 and the disc part 10 consist of respective sheet metal blanks whichtake on the ring shape in the case of the rim part 1 and the disc shapein that of the disc part 10 through shaping and cutting or punching, asis known in principle by the person skilled in the art. In order tofasten the vehicle wheel 1 to the vehicle hub, the central portion 11 ofthe disc part 10 is provided with a central aperture 12 and with fourbolt holes 13 offset to one another by 90° and arranged in the centralportion 11. In the exemplary embodiment shown, the central aperture 12has an edge 14 which is bent up towards the outside of the wheel. Thetransmission of force between the rim part 1 carrying the tyre and thecentral portion 11 connected to the vehicle hub is effected via fourspoke arrangements 15 formed by shaping the sheet metal and havingmultiple steps, each spoke arrangement 15 extending radially outwards inprolongation of one of the bolt holes 13. Each spoke arrangement 15 hasa plane central web 16 which is disposed orthogonally to the wheel axisR and which, viewed in the circumferential direction, merges on eachside into a lateral web 17 extending radially and bent from the plane ofthe central web 16 towards the outer side of the wheel, and then into anedge web 18 which is bent back again with respect to the lateral web,whereby each spoke arrangement 15 receives essentially an approximatelyU-shaped cross section, as is indicated schematically in FIG. 4.

As can be seen especially clearly in FIGS. 1 and 2, the width of eachspoke arrangement 15 decreases from the central portion 11 radiallytowards the outside up to the outer ends of the spoke arrangements 15.The outer ends of the four spoke arrangements 15, or the outer ends ofthe central webs 16 and of at least the lateral webs 17, merge into anannular disc edge 19. As can be seen especially clearly in FIG. 3, thedisc edge 19, especially in the region of the ventilation apertures 5,is disposed, completely or almost completely, exactly parallel to thewheel axis R. The disc edge 19, as a circumferential part of the discformed integrally from the starting blank for the disc part 10, connectsall four spoke arrangements 15 to one another. The disc edge 19 formsthe connecting part via which the disc part 10 is connected to theunderside of a drop centre 2 of the rim part 1, preferably via a weldedjoint, in order to form a vehicle wheel. The outer, exposed edges 18′ oftwo adjacent spoke arrangements 15, and the disc edge 19 disposedparallel to the wheel axis, delimit between two spoke arrangements 15large-area ventilation apertures 5, which accordingly extend over thewhole region between the edge webs 18 of two adjacent spoke arrangements15 and the disc edge 19. In the vehicle wheel 50 according to theinvention, the number of bolt holes 13 and the number of spokearrangements 15 is four, and a given bolt hole 13 and a given spokearrangement 15 lie mirror-symmetrically with respect to a common radialline R1. Accordingly, the vehicle wheel 50 has four ventilationapertures 5.

It can also be seen clearly in FIGS. 1 and 2 that the edge webs 18oriented towards the same ventilation aperture 5 in each case merge witheach other at the point of intersection with a radial line R2 which isdisposed symmetrically between two bolt holes 13 or two adjacent spokearrangements 15, and which therefore in each case bisects a ventilationaperture 5, viewed in the circumferential direction. The lateral webs 17of adjacent spoke arrangements 15 also merge with one another on thisradial line R2, and the disc part 10 has its greatest depth deformationalong this radial line R2.

The individual spoke arrangements 15 narrow towards the outside radiallyin such a way that, at the narrowest point of each spoke arrangement 15,which coincides substantially with the region of transition between thespoke arrangements 15 and the disc edge 19 and is denoted by referenceB′ in FIG. 1, the width of each individual spoke arrangement 15 is equalto or preferably less than 1/12 of the circumference of the disc part10. By contrast, the varying width of each spoke arrangement 15, viewedin the circumferential direction, is indicated generally by reference Bin FIG. 1. On the same reference circle around the wheel axis on whichthe individual spoke arrangements 15 have their narrowest width B′, theventilation apertures 5 correspondingly have their greatest arc length,which is indicated in FIG. 1 by reference L′. According to theinvention, this greatest arc length L′ is selected such that eachventilation aperture 15 extends over an arc length L′ which is equal toor preferably greater than ⅙ of the circumference of the disc part onthe same reference circle on which L′ and B′ lie. All four ventilationapertures therefore together extend over ⅔ or preferably more than ⅔ ofthe circumference of the disc part 10. The four spoke arrangements 15therefore together cover, at their smallest width B′, less than ⅓ of thecircumference of the wheel disc or of the disc edge. This has at thesame time the result that the individual ventilation apertures 5 eachextend over a maximum arc length L′ which is preferably more than twiceas great as the narrowest width B′ of a spoke arrangement 15.

At the same time, each ventilation aperture 5 has its maximum radialclear width on the radial line R2, and therefore on the radial linewhich in each case bisects the ventilation apertures 5 and on which theedge webs 18 and the lateral webs 17 of adjacent spoke arrangements 15merge into one another. The clear width W of each ventilation aperture 5on the radial line R2 is in this case dimensioned such that it is equalto or preferably slightly greater than the radial width S of the metalportion in the central region of the disc part 11 on the same radialline R2; the radial width S of the metal portion of the disc 10 refersin this case to the width between the internal circumference of thecentral aperture 12 and the outside edge 18′ on the radial line R2,where the definitions of the clear width W and of the radial width S ofthe disc part 10 relates to the plan view or projection of the wheeldisc shown in FIG. 1 and to the sectional view in FIG. 3, respectively.In particular, it can be seen especially clearly from the sectional viewin FIG. 3 that the wheel disc 10, as is apparent in the lower half ofFIG. 3, has its greatest depth or depth deformation V between theunderside of the central portion 11 and the upper side of the wheel discon the radial line R2, while the central webs 16 of the individual spokearrangements 15 are embossed approximately ⅓ less far outwards withrespect to the underside of the hub connection face.

As can again be clearly seen in the sectional view of FIG. 3, eachcentral web 16 extends parallel to the hub connection face andorthogonally to the wheel axis R over a relatively long radial partialsection, the length of this partial section being denoted by reference Tin FIG. 1. As a result, since all the spoke arrangements are identical,although offset circumferentially from one another, all thecorresponding radial partial sections of the central webs 16 lie in aplane which runs perpendicularly to the wheel axis R. The length T, overwhich the central webs 16 of all the spoke arrangements 15 are disposedperpendicularly to the wheel axis R, is in each case longer than halfthe clear width W of a ventilation aperture and in this case is in therange 0.6 T/W 0.7, more precisely approximately 0.67. From the plan viewin FIG. 1 and the perspective view in FIG. 2 it can also be clearly seenthat the edge webs 18 have a depth X which changes continuously, viewedin the radial direction, at first increasing continuously, starting fromthe centre of the ventilation aperture, and then decreasing continuouslyagain up to the spoke ends or the disc edge 19. At the same time, thedistance A between the lateral webs 17 of a spoke arrangement 15 (or thewidth of the central webs 16) also changes within each spoke arrangement15, which distance A, starting from the central portion 11 stillencompassing the bolt holes 13, first decreases continuously and thenincreases again.

The maximum relative deformation depth between the upper side of thecentral web 16 and the upper side of the edge web 18 is designated inFIG. 4 by reference Z and is preferably between 10 mm and 30 mm in therange of extent of the ventilation apertures, the minimum depth beinggreater than 10 mm in the region in which the central webs 16 aredisposed plane-parallel to the hub connection face and perpendicularlyto the wheel axis.

As can again be clearly seen in the plan view in FIG. 1, the outsideedges 18′ of the edge webs 18, starting from the disc edge 19, aredisposed obliquely at an angle to the radial line R1, this oblique anglebeing from 6° to 10° and preferably being approximately 8°±1°. FIGS. 3and 4 show further that the outside edges 18′ of the edge webs 18 andthe outside edges 19′ of the disc edge 19 are in each case disposedobliquely with respect to the wheel axis R.

In the second exemplary embodiment of a wheel disc 150 as shown in FIGS.5 and 6, the rim part 101 and the disc part 110 have almost the samestructure as in the previous exemplary embodiment and the centralportion 111 has, as in the previous exemplary embodiment, four boltholes 113, in prolongation of which in each case extends a spokearrangement 115 with central web 116, two lateral webs 117 which arebent towards the outside of the vehicle wheel 150 with respect to thecentral web 116, and two edge webs 118 which are each bent back again,with respect to the bend from central web 116 to lateral web 117,towards the rear side of a vehicle wheel 150. The edge webs 118 ofadjacent spoke arrangements 115 border large-area ventilation apertures105, and the disc edge 119 again runs exactly parallel to the wheel axisR in the region of the ventilation apertures 105. The radial width S ofthe metal portion of the disc part 110 and the clear width W of eachventilation aperture 105, and also the minimum width B′ and the greatestarc length L′ of the ventilation apertures 105 on the reference circleon which the minimum width B′ of the spoke arrangements 15 is located,have practically the same values as in the previous exemplaryembodiment, and L′ is greater than ⅙ of the circumference of the discpart 110 on this wheel disc circumference. The radial partial length T,along which the central web 116 extends orthogonally with respect to thewheel axis R, is, however, considerably shorter than in the exemplaryembodiment according to FIGS. 1 to 4, as can be seen especially clearlyin FIG. 6, as a result of which a quotient T/W in the lower limit rangeof 0.6 is arrived at for the vehicle wheel 150.

For the person skilled in the art, the preceding description will yieldnumerous modifications which shall fall within the scope of protectionof the appended claims. Although the arc length of the ventilationapertures is greater than ⅙ of the circumference of the disc part in allthe preferred exemplary embodiments, the arc length may neverthelessalso be equal to ⅙ of the circumference of the disc part or optionallyeven slightly less, without departing from the scope of protection ofthe appended claims. The central webs of the individual spokearrangements might also be disposed slightly obliquely with respect tothe wheel axis, even though the orthogonal orientation of the centralwebs is especially advantageous. The offset of the wheel disc in the rimpart is in each case preferably selected such that the surfacesprojecting furthest towards the outside of the wheel lie substantiallyflush with the outermost edge of the rim beads or further inwards, sothat the disc part in no case projects beyond the rim part. Such andfurther modifications shall come within the scope of protection of theappended claims.

In accordance with the provisions of the patent statutes, the principleand mode of operation of this invention have been explained andillustrated in its preferred embodiments. However, it must be understoodthat this invention may be practiced otherwise than as specificallyexplained and illustrated without departing from its spirit or scope.

The invention claimed is:
 1. A vehicle wheel for passenger carscomprising: a rim part for receiving a tyre and a disc part which isconnected to the rim part and is formed from a one-piece sheet metalblank by shaping and cutting or punching, which disc part includes acentral portion having bolt holes for wheel bolts, a central aperturefor a vehicle hub and a plurality of radially extending spokearrangements, formed by shaping the sheet metal, for transmitting forcebetween the vehicle hub and the rim part, each spoke arrangement havinga generally U-shaped cross section and being provided with a radiallyextending generally planar central web which merges on each side, ifviewed in a circumferential direction, into a radially extending lateralweb, bent outwardly from a radially extending plane of the central webover the entire radial length thereof, and then into an edge web bentback again with respect to the lateral web, radially outer ends of thecentral web and of the lateral webs merging into a circumferentialannular disc edge oriented precisely parallel or substantially parallelaxially to a wheel axis and connecting all the spoke arrangements to oneanother, which disc edge is formed integrally from the sheet metal,forms a connecting part for the connection between the rim part and thedisc part and delimits in each case, together with the edge webs ofadjacent spoke arrangements, ventilation apertures which extend over aregion between the edge webs and the disc edge, wherein the number ofspoke arrangements and the number of bolt holes is four and a spokearrangement and a bolt hole are in each case arrangedmirror-symmetrically with respect to a common radial line, a width ofeach spoke arrangement constantly narrowing radially towards an outside,starting from the central portion, each ventilation aperture extendingin a circumferential direction, at a narrowest point of the spokearrangements, over an arc length of more than ⅙ of a circumference ofthe disc part, and each ventilation aperture having in a radialdirection, on a radial line located midway between two adjacent spokearrangements, a maximum radial clear width which is equal to or greaterthan a radial width of the metal portion of the disc part on the sameradial line, wherein the central webs of all the spoke arrangements ineach case extend, in a radial partial section, in the plane thereofwhich is disposed orthogonally to the wheel axis, the partial sectionhaving a length which is greater than half of the clear width of theventilation apertures, and wherein the edge webs of each spokearrangement include at least a portion, adjacent an outer edge of eachedge web, which extends offset and parallel to the central web.
 2. Thevehicle wheel according to claim 1, wherein the ratio of the radialwidth to the clear width is from 0.85 to 0.95.
 3. The vehicle wheelaccording to claim 1, wherein the quotient of the length of the partialsection and the clear width is from 0.6 to 0.7.
 4. The vehicle wheelaccording to claim 1, wherein the edge webs have a depth which, startingfrom the radial line disposed midway between two adjacent spokearrangements, at first increases continuously and then decreasescontinuously again.
 5. The vehicle wheel according to claim 1, wherein adistance between the lateral webs of a spoke arrangement, starting fromthe central portion in the direction of the outer spoke ends, at firstnarrows continuously and then widens again.
 6. The vehicle wheelaccording to claim 1, wherein a maximum relative deformation depthbetween the central web and a transition of the lateral web to the edgeweb, in a range of extent of the ventilation apertures, is from 10 mm to30 mm, a minimum depth being greater than 10 mm in the region of aradial partial length.
 7. The vehicle wheel according to claim 1,wherein outside edges of the edge webs bordering the ventilationaperture in a radially outer region of the ventilation apertures aredisposed obliquely with respect to the common radial line of bolt holeand spoke arrangement at an angle from 6° to 10°.
 8. The vehicle wheelaccording to claim 1, wherein outside edges of the edge webs and of thedisc edge directly bordering the ventilation aperture are disposedobliquely with respect to the wheel axis.
 9. A vehicle wheel forpassenger cars comprising: a rim part for receiving a tyre and a discpart which is connected to the rim part and is formed from a one-piecesheet metal blank by shaping and cutting or punching, which disc partincludes a central portion having bolt holes for wheel bolts, a centralaperture for a vehicle hub and a plurality of radially extending spokearrangements, formed by shaping the sheet metal, for transmitting forcebetween the vehicle hub and the rim part, each spoke arrangement beingprovided with a radially extending central web which merges on each sideinto a radially extending lateral web, bent outwardly from a plane ofthe central web, and then into an edge web bent back again with respectto the lateral web, radially outer ends of the central web and of thelateral webs merging into a circumferential annular disc edge orientedprecisely parallel or substantially parallel axially to a wheel axis andconnecting all the spoke arrangements to one another, which disc edge isformed integrally from the sheet metal, forms a connecting part for theconnection between the rim part and the disc part and delimits in eachcase, together with the edge webs of adjacent spoke arrangements,ventilation apertures which extend over a region between the edge websand the disc edge, wherein the number of spoke arrangements and thenumber of bolt holes is four and a spoke arrangement and a bolt hole arein each case arranged mirror-symmetrically with respect to a commonradial line, a width of each spoke arrangement constantly narrowingradially towards an outside, starting from the central portion, eachventilation aperture extending in a circumferential direction, at anarrowest point of the spoke arrangements, over an arc length of morethan ⅙ of a circumference of the disc part, and each ventilationaperture having in a radial direction, on a radial line located midwaybetween two adjacent spoke arrangements, a maximum radial clear widthwhich is equal to or greater than a radial width of the metal portion ofthe disc part on the same radial line, wherein the central webs of allthe spoke arrangements in each case extend, in a radial partial section,in the plane thereof which is disposed orthogonally to the wheel axis,the partial section having a length which is greater than half of theclear width of the ventilation apertures, and wherein the edge webs ofeach spoke arrangement include at least a portion, adjacent an outeredge of each edge web, which extends offset and parallel to the centralweb.
 10. The vehicle wheel according to claim 9, wherein the ratio ofthe radial width to the clear width is from 0.85 to 0.95.
 11. Thevehicle wheel according to claim 9, wherein the quotient of the lengthof the partial section and the clear width is from 0.6 to 0.7.
 12. Thevehicle wheel according to claim 9, wherein the edge webs have a depthwhich, starting from the radial line disposed midway between twoadjacent spoke arrangements, at first increases continuously and thendecreases continuously again.
 13. The vehicle wheel according to claim9, wherein a distance between the lateral webs of a spoke arrangement,starting from the central portion in the direction of the outer spokeends, at first narrows continuously and then widens again.
 14. Thevehicle wheel according to claim 9, wherein a maximum relativedeformation depth between the central web and a transition of thelateral web to the edge web, in a range of extent of the ventilationapertures, is from 10 mm to 30 mm, a minimum depth being greater than 10mm in the region of a radial partial length.
 15. The vehicle wheelaccording to claim 9, wherein outside edges of the edge webs borderingthe ventilation aperture in a radially outer region of the ventilationapertures are disposed obliquely with respect to the common radial lineof bolt hole and spoke arrangement at an angle from 6° to 10°.
 16. Thevehicle wheel according to claim 9, wherein outside edges of the edgewebs and of the disc edge directly bordering the ventilation apertureare disposed obliquely with respect to the wheel axis.